GB-A-1,582,201 describes such a load attachment system. The elongate element, which may be rigid or flexible, is generally fixedly secured at its ends to the support structure as well as being located, at intermediate locations, with respect to the structure. The system includes a load-transfer or traversing device which is utilized to locate the elongate element at each intermediate location point, or is engaged with the elongate element to move therealong with the ability to traverse the intermediate support points without needing to be detached from the elongate element.
When a wire element is utilized for the elongate element, for example, it is usually provided with end ferrules or sleeves swaged thereon, provided with integral couplings for bolting to location fittings secured to a fixed structure. In many applications where a personnel safety line is concerned, a shock absorbing and line tensioning device, e.g. as described in EP-A-0,212,826, is interposed between the end ferrule of the wire and a location fitting to facilitate initial installation tensioning of the wire and to absorb shock loading applied to the wire in use.
The invention is therefore concerned with providing an improved shock absorbing device adapted to control the peak loading applied to the attachment means secured to the fixed structure.
The invention provides a shock absorber comprising two relatively movable parts for connection between an elongate support or location element and a fixed supporting support for the elongate element, one of said parts being provided with a tubular element and the other of said part being provided with a loading member extending through the tubular element and provided with outwardly projecting flange means which is adapted, under normal loading, to remain located against an end surface of the tubular element and, under greatly increased loading, to be pulled into the tubular element to cause a radially outward deformation of the wall of the tubular element thereby acting to absorb such loading.
Preferably at least one of the contacting surfaces on the flange means and the internal surface of the tubular element is provided by a lubricating material.
Such flange part may be provided by a nut threadably mounted on a section of said loading member. The nut may have a tapered end section which engages within a smoothly profiled internal end surface of the tubular element even before any outward deformation thereof. In other embodiments, the flange part may include at least one rolling element which engages the end surface of the tubular element to cause outward deformation thereof under greatly increased loading conditions.